When a fault occurs in the control system (electronic control unit (ECU), various sensors, etc.) of a vehicle, the driver recognizes the fault based on the occurrence of an abnormal symptom, lighting of a warning lamp, or the like, and brings the vehicle to a dealer or a repair shop.
The worker (technician) who is in charge of repairs uses an external diagnosing apparatus to read a diagnostic trouble code that was stored in the ECU of the faulty vehicle at the time that the fault occurred, thereby grasping a faulty event (e.g., in the event of an abnormal output value from a sensor, the content of the abnormal output value). Then, the worker identifies a faulty spot that is responsible for the faulty event by successively confirming whether or not components are normal based on a service manual or the like.
There have been developed diagnosing apparatus for use in identifying faulty spots as described above (Japanese Patent Publication No. 07-076720, hereinafter referred to as “JP07-076720B”, and U.S. Patent Application Publication No. 2001/0002450, hereinafter referred to as “US2001/0002450A1”). According to JP07-076720B, the diagnosing apparatus reads trouble data stored in a vehicle ECU and converts the trouble data into a trouble code. The diagnosing apparatus also stores in a memory cartridge fault detail data corresponding to the trouble code in a service manual, and displays an identification symbol (fault abbreviation, etc.) corresponding to the trouble code (Claim 1).
According to US2001/0002450A1, the worker performs a fault diagnosis while interacting with a computer (fault diagnosing apparatus (1)) (see Abstract). More specifically, the fault diagnosing apparatus (1) displays HTML data according to an inspection procedure based on a flowchart shown in FIG. 4 in order to indicate a fault diagnosis sequence in an interactive way (paragraph [0040]). Specific display contents are shown in FIGS. 5A and 5B (paragraph [0040]). According to US2001/0002450A1, furthermore, in the event of a fault diagnosis, vehicle data are automatically acquired from an ECU and displayed (Abstract, FIGS. 5A through 7, paragraph [0053]).